Community-level reorganizations following migratory pollinator dynamics along a latitudinal gradient

Predicting how communities re-arrange in response to changes in species
composition remains a key challenge in ecology. Migratory species, which
enter and leave communities across latitudinal gradients, offer us a
unique opportunity to evaluate community and species-level responses to a
shift in community composition. We focused on a migratory hummingbird and
the communities that host it along a latitudinal and species diversity
gradient. Our results show higher niche overlap in more diverse
communities, allowing resident species to compensate for the loss of the
migrant in providing pollination services. Contrastingly, in less diverse
communities, the migrant behaves as a specialist, monopolizing abundant
resources. In its absence, its role is not fully covered by resident
species, resulting in a decrease in the fruit set of the migrant´s
preferred plant species. These results help us understand the potential
impacts of biodiversity loss and have important implications for community
persistence given expected changes in the migratory behaviors of some
species.